1885.] TROCHILID^E, CAPRI MULGID.E, AND CYPSELTD.E. 905 



against the coracoids, their apices extending backwards to touch 

 either scapula. In Nuttall's Whippoorwill an outer ledge is deve- 

 loped on either clavicular head to abut against the corresponding 

 coracoid in front, a feature which is still better displayed on the 

 part of the CypselidcE ( Plate LX. fig. 2, z). 



A scajiula in the Night-hawk has the typical blade-like portion, 

 which is more inclined to be truncated in Phalcconoptilus. Both 

 birds have its head broad transversely, and somewhat flattened from 

 above downwards. When articulated it rests upon rather a meagre 

 scapular process of the coracoid, with its inner angle extended for- 

 wards to meet the clavicle, as already defined above. 



The elements of the jiectoral arch seem to be non-pneumatic bones 

 throughout the CoprhmilfjklcB. 



Of the remainder of the Cypseline Axial Skeleton. — We find in 

 the cervical region of tlie column of P niijptHa saxatilis twelve 

 vertebrae before meeting that one in which the pleurapophyses have 

 become liberated as ribs. These latter are here of the most rudi- 

 mentary character ; for in a specimen before me, on one side the rib 

 is merely represented by a minute rod of bone suspended from 

 beneath the transverse process, while on the opposite side the head 

 of the bone is found, and the whole is rather more advanced. Tlie 

 atlas is more than usually delicately conslructed, while the axis is 

 very narrow in the antero-posterior direction. 



A shallow carotid canal seems to be confined to the fourth and 

 fifth vertebrae, the usual process taking its place after that. All 

 these vertebrae, as a rule, are notably short, with well-developed pre- 

 and post-zygapophyses. 



Beneath, the parapophyses arc as long as the centra, and are 

 placed rather close together on each vertebra. 



The articulations are of the heterocoelous type, and the lateral 

 canals are very short. One very interesting feature is seen in this 

 part of the spinal column of the White-throated Rock-Swift, and 

 that is the ossification of the interspinous ligaments among the 

 ultimate segments. The neural spines of the tenth, eleventh, twelfth, 

 and thirteenth vertebrae are low and inconspicuous, and the fine 

 thread-like ligament that joins these processes lias become thoroughly 

 ossified, the minute osseous rods thus formed articulating, at either 

 end, with the neural spines of the vertebrae in question. These 

 vertebrae, in Panyptila, are essentially very different from the corre- 

 sponding bones in Trochilus. 



The fourteenth vertebra possesses a pair of free ribs, which may 

 or may not have uniform appendages near their lower extremities ; 

 and this segment has likewise many of the characteristics of tlie 

 dorsal series that follow. 



Below it develops a (ricornuate hypapophysis, this process being 

 markedly prominent on all the succeeding vertebrae, occurring al<o 

 upon the first two in the sacrum, an unusual thing. The presence 

 of this formidable series of hypapophyses is accounted for by the 

 same law that demands their presence in Colymhus, the sole differ- 

 ence being that, while the latter, by the aid of his strong wings, passes 



